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spst and dpdt switches amperage?

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Posted by phillipbayly on Wednesday, May 19, 2010 6:18 PM
thanks everyone. this is s big help and now to get too it. Regards Phil
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Posted by mokenarr on Tuesday, May 18, 2010 12:49 PM

 the current , like 5 amp. is the maximuin current the switch can handle at any voltage..  when a switch says 120v 5 amps or 250 volts 3 amps , its due to the possible arcing , which is more at 250 volts..   so if its 5 amps at 120 volts its also 5 amp max at 14.5 volts. 

Old Steam loco's never die, they just lose thier fire.
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Posted by richhotrain on Tuesday, May 18, 2010 7:36 AM

cacole

I was forced to patronize Radio Shack

LOL

Alton Junction

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Posted by cacole on Tuesday, May 18, 2010 7:30 AM

P.S. to my earlier reference to All Electronics:

Monday, May 17th, I was forced to patronize Radio Shack for a DPDT Miniature ON-OFF-ON toggle switch to replace one on a portable HO scale layout that we raffled off during our weekend open house, which got broke by the people who moved the layout.

Radio Shack's price was $5.30.  All Electonics' price for the exact same item is $1.60 or 10 for $13.00.

Shipping from All has to be taken into account, but if you order more than just toggle switches, which I nearly always do, the savings can be significant.

 

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Posted by tomikawaTT on Monday, May 17, 2010 7:11 PM

If you are only killing a track, presumably so a standing locomotive will stay standing or to turn off the lights in a passenger train, why do you need a DPST?  If you turn off either rail the track will be just as dead as if you had cut the feeder wire with diagonal pliers - which, electrically, is what a SPST switch does.

Even very inexpensive slide switches are rated 5 amps - as are the mini relays I use to control hot frogs.  IMHO, using more than the absolute minimum number of contacts complicates the wiring and drives up expenses unnecessarily - and this hobby is complicated and expensive enough already.

Chuck (Modeling Central Japan in September, 1964)

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Posted by dbduck on Monday, May 17, 2010 6:40 PM

 

(dpst toggles are not all that common at local stores)

 You can use a DPDT as a DPST by only using the center terminals & one outside set of ternimals

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Posted by gandydancer19 on Monday, May 17, 2010 2:51 PM

cacole

DCC track voltage is in the range of 14.5 Volts.  The amount of Amperage on the track depends on your DCC system's booster output and the current draw of the items on the track; usually no more than 1 or 2 Amps max. 

Toggle switches are usually rated for 110 Volts AC, so one rated at 1 Amp would be more than sufficient.

If the 5 amp power supply is going to be used for the Tortoise switch machines, they will still draw only 10-15ma each so a toggle switch rated for 1 amp @ 110 Volts AC would be more than sufficient.

 

I agree.  You are not going to be using one of these switches to turn your layout on and off.  Switches for track power in DCC are mostly used for engine house tracks etc that only hold one or two locomotives.  Maybe some yard tracks.  But you don't have to use switches for block control like you did for DC.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

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Posted by mobilman44 on Monday, May 17, 2010 7:59 AM

Hi,

I just picked up 5 dpst toggles to isolate staging tracks & loco terminal tracks on my HO DCC layout.  I wrestled with the same question you have, but found a deal for the toggles (dpst toggles are not all that common at local stores) on Ebay that were rated at 15 amps (for 110v).  I assume this is overkill (story of my layout construction history), but they are substantial and I'll never need worry about them.

I would have picked up the same type toggles at 5 amps (for 110v), and they would have worked just fine.  But...........

Mobilman44

ENJOY  !

 

Mobilman44

 

Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central 

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Posted by richhotrain on Monday, May 17, 2010 7:33 AM

I use a 5 amp DPDT from Miniatronics.  It is a miniature toggle switch, not as small as the ulta-miniature switch that cacole referred to, but still only about 1/2 inch square.  The rating shown on the package is 120VAC/28VDC. 

It costs around $2.50 per switch and Miniatronics sells them individually or in packages of 4, and maybe in packages of 8, if my memory serves me correctly.

Alton Junction

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Posted by cacole on Monday, May 17, 2010 6:56 AM

For what purpose are you using these switches? 

A Tortoise switch motor draws only 15ma at 12 Volts or less, so any toggle switch should be okay for them.  I use DPDT ultra-miniature switches purchased from All Electronics or other surplus dealers.

DCC track voltage is in the range of 14.5 Volts.  The amount of Amperage on the track depends on your DCC system's booster output and the current draw of the items on the track; usually no more than 1 or 2 Amps max. 

Toggle switches are usually rated for 110 Volts AC, so one rated at 1 Amp would be more than sufficient.

If the 5 amp power supply is going to be used for the Tortoise switch machines, they will still draw only 10-15ma each so a toggle switch rated for 1 amp @ 110 Volts AC would be more than sufficient.

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spst and dpdt switches amperage?
Posted by phillipbayly on Monday, May 17, 2010 6:30 AM
I am building my first DCC layout after several DC layouts, so this is familiar and not. I am using Lenz 100 system and peco code 83. I am planing to installing tortoise switches (fist time using them) and reversing loops. I went to buy a number of single pole single throw switches buy was then asked what amp switches I need. My transformer is made by a friend and is a 5 amp monster. Does this mean I would want 5 amp spst and dpdt switches? Appreciate any thoughts on this as I have no idea what to do. Regards Phil
Tags: DCC , DPDT , Switches , Tortoise , Wiring

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